In stereoscopic planetarium projection, two approaches have been pursued: (1) a rectangular “inset” image is projected in the front of a dome by a single projector or a pair of left eye/right eye perspective image projectors located behind the audience, near the edge of the dome and (2) multiple projectors, located near the edge of the dome, project an edge-blended image that covers the whole or most of the dome, often with blend zones in the central areas of interest in the projected image.
An inset image may not take full advantage of the immersive nature of a projection dome. On the other hand, edge blended systems with multiple projectors at multiple locations can be complicated to install and maintain well aligned.
Therefore, a single projector system or dual left eye/right eye perspective projector system where the projector(s) are located behind the audience in the rear of the dome, and illuminate(s) a large enough section of the dome to create an immersive, “frameless” feeling is desirable.
Further, it is desirable to use standard cinema components, including standard cinema three-dimensional (3D) glasses and 3D glasses handling equipment, in order to keep operational costs down.